Accessories are normally assembled on a ski by means of screws. In general, the ski is preliminarily drilled with holes, for which the center distance of axes corresponds to that of the screws used to assemble the accessory in question. The accessory is placed in position on the ski, then the screws are tightened one by one.
In the past, screws were packaged separately from the bindings. The retailer was therefore obliged to open the bag of screws, place the screws in their respective holes, and screw them in one by one. The positioning of the binding on the ski, i.e., matching up the holes in the binding with the pre-drilled holes in the ski, was a complex operation, since it was done "blind," i.e., by trial and error.
French Patent Application No. 2 208 692 made known an assembly technique according to which the screws are held in place ready to be screwed into the base of the binding using a deformable position-retention device which holds them firmly in place. To facilitate the installation of the binding on the ski, the screws are held in place with the tip protruding beneath the lower surface of the binding. When the position of the binding on the ski matches the position determined by the holes pre-drilled in the ski, the tips of the screws fall into the holes, an occurrence which is easily sensed.
The technique described in this patent application requires the use of one or several elastically-deformable position-retention devices. These devices include, for example, an interface plate which is inserted between the lower surface of the binding and the upper surface of the ski, and deformable bushings embedded in the holes of the binding.
This technique can also be used without any additional position-retention device. Each screw is, in this case, held in place by the wall itself of the hole in the base, which can be made of a deformable material, e.g., a plastic material, or a non-deformable material, e.g., a metal-based alloy.
The problem then arises of ensuring with precision the placement of each screw in its hole, so that a well-determined length of the screw protrudes beneath the lower surface of the binding, in order to facilitate the installation of this binding on the ski.
In fact, since the screw is inserted in its hole by force, it is difficult to position it with precision on the production line, with the tip protruding beneath the lower surface of the binding and the head raised in relation to its housing.
This constraint causes problems on the production line itself, where the binding must be completely immobilized by its base so as to simulate disengagement and to control its operation. Imprecise placement of the screws can, in this case, hinder the operation of the elements which immobilize the base.
Furthermore, during mounting of the binding on the ski, if the screw is not sufficiently inserted in its hole and does not protrude sufficiently, installation of the binding on the ski will occur by trial and error, as before, and will be time-consuming for the retailer. If the length of the screw protruding beneath the lower surface of the binding is excessive, there is a risk of splintering the base of the binding during the screwing operation, since this screw holds, in localized fashion, the base raised in relation to the upper ski surface, while, when the other screws are tightened, they tend, on the contrary, to press the base down against the upper ski surface.